[SCSI] drivers/scsi/sr_ioctl.c: check for failed allocation
[SCSI] drivers/scsi/sr_ioctl.c: check for failed allocation

I noticed a case in sr_ioctl.c's sr_get_mcn where a buffer is
allocated, but the pointer isn't checked for null.

Signed-off-by: Nate Dailey <1984f99ab51ed29f74d87e5456a93884655805e5@stratus.com>
Signed-off-by: James Bottomley <407b36959ca09543ccda8f8e06721c791bc53435@SteelEye.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs